Wear blade for snowmobile skid suspension

ABSTRACT

This invention relates to a novel elongate replaceable wear blade suitable for use with snowmobile suspensions of the type having a longitudinally extending skid adapted to resiliently apply to the ground engaging portion of the snowmobiles track at least a portion of the vehicles weight. The blade is formed from a hard, wear resistant synthetic resin and has along one side thereof an elongate restricted channel opening. The channel is adapted to be slidingly engaged and retained by complementary means on the skid. Abutment means are provided on the skids to hold the blades in a fixed position relative to the skids.

United States Patent [1 1 Bombardier Nov. 6, 1973 WEAR BLADE FORSNOWMOBILE SKID SUSPENSION Inventorz Emile Bombardier, Lawrenceville,

Quebec, Canada Assignee: Bombardier Limited, Valcourt,

Quebec, Canada Filed: Feb. 14, 1972 Appl. No.: 225,771

U.S. Cl. 305/24 Int. Cl 362d 55/10, B62m 27/02 Field of Search. 180/5 R;305/24;

References Cited UNITED STATES PATENTS Erickson 180/5 R 4/1972 Perreault305/24 488,266 l2/l892 Jordan 280/28 Primary Examiner-Richard J. JohnsonAtt0rneyChrist0pher Robinson et al.

[57] ABSTRACT This invention relates to a novel elongate replaceablewear blade suitable for use with snowmobile suspensions of the typehaving a longitudinally extending skid adapted to resiliently apply tothe ground engaging portion of the snowmobiles track at least a portionof the vehicles weight. The blade is formed from a hard, wear Iresistant synthetic resin and has along one side thereof an elongaterestricted channel opening. The channel is adapted to be slidinglyengaged and retained by complementary means on the skid. Abutment meansare provided on'the skids to hold the blades in a fixed positionrelative to the skids.

5 Claims, 6 Drawing Figures WEAR BLADE FOR SNOWMOBILE SKID SUSPENSIONSUMMARY OF THE INVENTION members are formed from elongate 'box shapedchannels to which wear blades are attached to the underside thereof bymeans of rivets. In use, it has been found that the wear blades canbecome worn to a sufficient degree that their. replacement is required.When the snowmobile is used in mud-snow or ice conditions, sand or thelike abrades the blade as the endless-track continuously rotates.Further, normal wear attributable to the frictional contact between thewear blades and the metal cleats positioned between the drive sprocketholes in the endless track or othermetallic members of the track isincreased when the track is rotated at high speeds for prolonged periodsof time or where the suspension system is subjected to rough treatmentasis-the case in racing. Furthermore, in certain skid'systems excessivewear is encountered near the extremeties of the wear blades as theendless track and its accompanying cleats are free to flex prior to therotating tracks introduction to the blades and just after the trackleaves the blades. Such systems, of course, are more likely to requirefrequent wear blade replacement.

Heretofore, blades-which were worn required a complete dismanteling ofthe suspension assembly from the vehicle chassis. Rivets, mounting boltsand the like had to be removed with the worn blade and then replacedlongitudinal movement of runners therealong. Runners as disclosed inU.S. Pat. No. 3,658,392 aforesaid serve to pivotally and slidablyconnect downwardly biased trailing arms on the chassis to the skids orskid members. The runner is provided with a channel complementing theupper retaining portion of the skid and preferably is formed from thesame material as the blade. For lightness, the skids or skid members areadvantageously made from extruded aluminum.

BRIEF DESCRIPTION OF THE DRAWINGS ing means for retaining the blade onthe skid element;

FIG. 4 is a cross-section taken along IV IV of FIG. 1 showing the stopelement used on the rearskid,

FIG. Sis a cross-section of a blade and skid illustrating a differentform of skid and blade channel, and

FIG. 6 is a section similar to FIG. 5 illustrating a further bladeconfiguration and including a runner mounted on the top portion of theskid.

DETAILED DESCRIPTION The skid suspension shown in FIG. 1 is similar tothat disclosed in U.S. Pat. No. 3,658,392 although only one with the newblades. This blade exchange required considerable time and in themajority of cases, could not be done by the snowmobile owner orenthusiast himself. In endurance racing, time lost in a pit stop forblade replacement weighed heavily in-the outcome of the race. I

The foregoing disadvantages have been overcome by a novel quick changewear blade. Essentially, the blade is made from a hard, wear resistantsynthetic plastic, such as ultra high density polyethylene, polyurethane, nylon or Teflon (trade mark)-and is provided with an elongatechannel or slot having a restricted opening running its full length. Thechannel is slidingly engageable with complementary retaining means onthe underside of the skid and held in position by an abutment or othersuitable locking means preferably provided on the trailing end of theskid. Although the replaceable wear blade hereinafter to be described indetail may be advantageously used on varying types of slide or skidsuspension systems, it has particular adaptation to articulated skidsuspensions wherein each skid includes two skid elements arranged in anend-to-end relationship and preferably pivotally connected to oneanother.

While the blade and channel may be of any desired side of the suspensionhas been shown. The suspension illustrated comprises two parallel skids,each skid having two skid elements '1 and 2 pivotally connected inend-to-end relationship for articulation. Endless track 3 is entrainedabout drive and idle sprockets (not shown). Metal cleats 4 positionedbetween the sprocket holes of the track contact blade 5 on front skidelement 1 and blade 6 on rear skid element 2.

Four trailing arms 7 are pivotally connectedto the snowmobile chassis(not shown) in a conventional manner and extend downwardly andrearwardly to form a pivotal connection with the skids. Pivot pins 8at-the lower extremeties of arms 7 afford the pivotal connection withthe skids. In FIG. 1, the rear three trailing arms 7 are alsoconstrained for longitudinal movement relative to the skid elements bybeing connected thereto by means of runners 9 discussed-in greaterdetail below. The front'or leading trailing arm 7 is directly pivotallyconnected to the skid element 1 by means of a mount or cross-bracer 24welded thereto. Springs 10 function to bias arms 7 downwardly andforwardly in a conventional manner.

Each skid, which may comprise two skid elements 1 and 2 as illustratedor just one continuous rail the length of which is slightly less thanthat of the ground engaging portion of the endless track, is preferablyformed from extruded aluminum having an I-shaped cross-section. As bestseen in FIG. 2 and 3, skid element 1 receivingly retains blade 5 whichis provided with a complimentary channel or slot. Other skidconfigurations are possible," as evidenced by the dumbbell cross-sectionof the skid 11 shown in FIGS. 5 and 6. Blade 12 illustrated in FIG. 5 isrectangular in crosssection but is provided with a C-shaped channel tocompliment the lower portion of skid 11. The blade 13 of FIG. 6 on theother hand has a C-shaped channel but is cylindrical in cross-section.This latter Configuration in certain conditions minimizes the frictionalcontact between the blade and cleats 14 against which it bears.

Referring now particularly to FIGS. 3 and 4, the rear of front orleading skid 1 is provided with locks 15 which serve the two foldpurpose of retaining blade in position and pivotally connecting thefront skid element 1 to rear skid element 2. Each lock is provided witha front outwardly projecting flange 16 which abuts the front portion ofanotch 17 provided in blade 5 in order to stop the blade from movingrearwardly. The locks are held in position by bolt means 18', the boltextending through skid l. The trailing ends of each of the locks arealso provided with a further hole for pivot pin 18 used for connectingthe front skid element to the rear element. The locks effectively formcheek plates which receivingly engage for pivotal action a centralprojection provided on the forward portion of rear skid element 2. Locksmay also serve to restrict the forward displacement of blade 6 on rearelement 2. In an alternative embodiment, locks 15 can be positionedabove blades 5 and 6 so as to function solely as a coupling means forarticulated skids l and 2. In such a case, the front blade 5 can be heldin position by means of a transverse pin (not shown).

The trailing portion of rear skid element 2 is provided with transverseabutment flanges 19 which effectively stop the rearward displacement ofblade 6 mounted thereon.

In the articulated suspension illustrated, blades 5 and 6 are readilyremoved'and replaced in the following manner. Pin 18 is removed and rearskid 2 displaced downwardly slightly from skid 1 thereby facilitatingthe forward sliding withdrawal of blade 6. Bolt means 17 and locks 15are removed from element 1 and blade 5 withdrawn rearwardly. As a tightsliding connection between the blades and skids is preferred, a malletmay be necessary to effect removal and replacement of the blades. Thisis particularly true with respect to the front blade as it is necessaryto upwardly deform the forward portion of it in order to have it take upthe upward configuration of skid 1. Depending upon the radius ofcurvature of the upwward curvature of the front blade (and the rearblade if it to is upwardly curved as disclosed in Application Ser. No.095,051, filed in Canada on Oct. 7, 1970), the curving action of theblade can be eased by slotting or providing the blades with V- shapedtransverse cuts as shown at 30. In the embodiment illustrated, the frontand rear replacement blades are inserted merely by reversing the aboveprocedure.

The runners 9 illustrated in FIGS. 1 and 6 each include a shoe 20provided with a slot or channel complimenting the retaining means on theparticular crosssection of the skid employed. Advantageously, theshoe isformed from the same material as the blade and includes the same channelcross-section as the blade. Fixedly mounted on the upper surface of shoe20 is U- shaped member 21 provided with holes 22 for pivotallyconnecting the runners 9 to the trailing arms 7 by means of pivot pins8.

As the majority of snowmobiles are designed for forward progressiononly, it will be seen that the track, rotating in a counter-clockwisedirection viewed in FIG. 1, forces blades 5 and 6 rearwardly. If thesnowmobile is provided with a reverse, then the rear portion of theblades can be provided with inclined tips similar to tip 23 on blade 6.While it is not necessary to provide a stop or abutment on forward skid1 due to the binding action of blade 5 thereon, suitable abutment meanscan also be provided at the forward end thereof. It is also desirable,in practice, to use skids or skid elements which are of identical lengthso that identically constructed replacement wear blades can be usedthroughout the suspension assembly.

What I claim as my invention is:

1. In a snowmobile suspension having a pair of spaced parallel elongateskids supported for sliding engagement against the ground-engagingportion of a track belt, each skid comprising a front skid section and arear skid section pivotally interconnected, the improvement that eachsaid skid section has a lower portion defining transversely projectingflanges and of constant cross-section throughout its length said lowerportion being received in a replaceable wear blade of constantcross-section having a longitudinal restricted channel opening of ashape complementary to the cross-section of the lower portion of saidskid section, releasable abutment means located at the pivotalinterconnection of said front and rear skid sections, further abutmentmeans at the rear end of said rear skid section, said abutment meansbeing operative to prevent sliding disengagement the wear bladesrearwardly from the corresponding front and rear skid sectionsrespectively, said releasable abutment means being disengageable topermit rearwards sliding withdrawal of the wear blade of the front skidsection, and forwards sliding withdrawal of the wear blade of the rearskid section.

2. A snowmobile suspension as claimed in claim 1,

wherein said skids have an I-shaped cross-section.

3. A snowmobile suspension as claimed in claim 1, wherein said skids areformed from extruded aluminum and said replaceable wear blades areformed from a hard, wear resistant synthetic resin.

4. A snowmobile suspension as claimed in claim 1 wherein each front skidsection has an upwardly curved forward end portion, the forward endportion of the corresponding wear blade having a number of spacedtransverse notches opening from its upper side, to facilitate bending ofthe wear blade to conform to the upward curvature of the forward endportion of the front skid section.

5. A snowmobile suspension as claimed in claim 1 wherein said front andrear skid sections are of L of the latter to the corresponding rear skidsection.

1. In a snowmobile suspension haviNg a pair of spaced parallel elongateskids supported for sliding engagement against the ground-engagingportion of a track belt, each skid comprising a front skid section and arear skid section pivotally interconnected, the improvement that eachsaid skid section has a lower portion defining transversely projectingflanges and of constant cross-section throughout its length said lowerportion being received in a replaceable wear blade of constantcrosssection having a longitudinal restricted channel opening of a shapecomplementary to the cross-section of the lower portion of said skidsection, releasable abutment means located at the pivotalinterconnection of said front and rear skid sections, further abutmentmeans at the rear end of said rear skid section, said abutment meansbeing operative to prevent sliding disengagement the wear bladesrearwardly from the corresponding front and rear skid sectionsrespectively, said releasable abutment means being disengageable topermit rearwards sliding withdrawal of the wear blade of the front skidsection, and forwards sliding withdrawal of the wear blade of the rearskid section.
 2. A snowmobile suspension as claimed in claim 1, whereinsaid skids have an I-shaped cross-section.
 3. A snowmobile suspension asclaimed in claim 1, wherein said skids are formed from extruded aluminumand said replaceable wear blades are formed from a hard, wear resistantsynthetic resin.
 4. A snowmobile suspension as claimed in claim 1wherein each front skid section has an upwardly curved forward endportion, the forward end portion of the corresponding wear blade havinga number of spaced transverse notches opening from its upper side, tofacilitate bending of the wear blade to conform to the upward curvatureof the forward end portion of the front skid section.
 5. A snowmobilesuspension as claimed in claim 1 wherein said front and rear skidsections are of I-shaped cross-section each having a vertical web, andwherein said releasable abutment means comprises a pair of abutmentplates arranged at the rear of each front skid section on opposite sidesof the web thereof and releasably secured thereto by fastener means,said abutment plates extending rearwardly of the front skid section anddefining means for pivotal interconnection of the latter to thecorresponding rear skid section.